As semiconductor technology has constantly been improving, the use of field effect transistors (FETs) has become more prevalent in all facets of computer and communications technology. This technological improvement has allowed for faster operation and more compact arrangement of FETs within integrated circuit (IC) chips. IC chips are widely used in all electronic equipment, including equipment that is manufactured and operated in harsh environments. However, such harsh environments increase the likelihood of exposure of IC chips to high-voltage electrostatic discharge (ESD) strikes, to which IC chips are highly vulnerable. The high current that results from ESD strikes breaks down the internal semiconductor material of the FETs, resulting in damage to the IC chip. The vulnerability of IC chips to ESD strikes has created an important need for ESD protection circuits.
It is known in the art to use a silicon-controlled rectifier (SCR) circuit to protect an IC chip from ESD strikes. A SCR circuit utilizes two bipolar junction transistors (BJTs), one NPN type and one PNP type, coupled together. The two BJTs are operative, upon being triggered by an ESD strike, to shunt current resulting from the ESD strike (e.g., to ground), thus creating a path away from the more delicate semiconductor material and saving the FET, and thus the IC chip, from damage. SCR circuits are now commonly used in many electronic devices for this ESD protective purpose. However, SCR circuits are bulky and are typically configured external to the IC chip that they are intended to protect.